The present invention relates to an absorbent product such as an incontinence pad, a sanitary pad, a diaper, another absorbent garment, or an absorbent inlay for such a garment, or the like, for absorbing bodily exudates. In particular, but not exclusively, the invention relates to absorbent products which are disposable after use (i.e. of the type which have materials which are not intended to be washed and used several times). Still more particularly, the invention relates to incontinence products, especially for use by adults, primarily but not exclusively for adult feminine use.
Typically, absorbent products of the above-mentioned type have an absorbent core surrounded by an envelope comprising a fluid-impermeable sheet or layer (commonly referred to as a back sheet) and a fluid-permeable sheet or layer (commonly referred to as a liner, top sheet or bodyside layer). In order to provide relatively fixed positioning of such products with respect to the wearer""s undergarment, friction-increasing means, such as one or more strips of pressure sensitive adhesive or the like, are applied to the outer surface of the back sheet. The presence of the friction-increasing means helps to inhibit movement of the absorbent product with respect to the undergarment by frictional engagement therewith. Prior art products of the this type are known in the art. In order that absorbent products conform better to the shape of users, and in particular to the wearer""s genitals, it is desirable to form absorbent products with a bowl or basin shape therein. Such a shape improves comfort.
Prior art solutions to said problem involve manufacturing methods including moulding articles into a basin-shape, or methods in which basin-shaped inserts are fitted into the absorbent products to hold said products in the desired shape. Further solutions are known in which parts of the sides of said products are provided with elastication to pull the product into the desired shape. However products formed in these ways typically involve manufacturing complications. Moreover such products do not naturally lie flat unless forces are applied to them to hold them flat, which can lead to packaging difficulties.
One object of the present invention is to provide a basin-shaped form in an absorbent product which provides an improvement over the prior art.
A further object of the invention is to provide an absorbent product which can be manufactured as a substantially flat article, but which can simply be transformed into a basin-shape.
In co-pending, non-published Swedish application No. 9701381-7, a solution to the above problem is proposed, whereby one or more pleats is provided in the impermeable back sheet of the product. Due to the use of an openable pleat, the inner folded edge of said pleat is superposed on to the remaining surface of the back sheet. In that patent application, the inner folded edge is movable independently of the absorbent core above, but the remainder of the back sheet (which is in contact with the absorbent core) can only be moved laterally together with the absorbent core. Consequently, the absorbent core can be subject to tension forces when said pleat is opened out.
It is also a further object of the present invention to provide an absorbent product which can hold, or in other words which can xe2x80x9cself-lockxe2x80x9d the absorbent product into a basin-like shape.
It is also known to provide prior art products with elastication in the areas of the product adjacent the wearer""s legs. In such a way a better, or tighter, fit of the product can be achieved and prevention of leakage of bodily fluids is improved. However, in many types of absorbent product, the elastication can be problematic. For example in a feminine incontinence pad, during the wearer""s movements (such as walking or sitting down), a problem may arise since the outer surface of the central part of the absorbent product is held essentially in place against the wearer""s undergarment by friction and also against the wearer""s genitals by friction, whilst the edge portions of the absorbent product are further held by friction against the inner regions of the thighs for example. Thus when the wearer moves, although elastication may provide a reasonable seal against leakage while still allowing for movement, the wearer may experience discomfort due to the opposing forces at the central portion and the outer portions, which tends to twist the product. Additionally, a problem may arise in that, due to the wearer""s movements, openings at the side edges of the product may indeed be created or enlarged, which can lead to undesirable leakage.
The aforementioned problem is often made worse by the use of friction-increasing means, such as pressure-sensitive adhesive, on the back sheet of absorbent products for fixing the central position of the product with respect to the undergarment, since slippage between the product and the wearer""s undergarment is substantially prevented. However, such friction-increasing means is generally desirable per se since there are other advantages in maintaining the central part of the product in a fixed position in the undergarment.
Another object of the invention is therefore to create a product which allows for movement of the side portions relative to the central portion, in particular when the central part of the product is fixed to said undergarment.
Since the human anatomy varies greatly, also in the crotch region where said absorbent products are worn, it is desirable to create absorbent products which can adopt different dimensions.
It is therefore another object of the invention to provide an absorbent product which has means allowing a variation in the lateral width thereof (i.e. in the width direction of the product).
It is furthermore desirable that the product is able, automatically, to adopt different lateral widths during use, so as to take account of any variations in, for example, the distance between the wearer""s thighs as a result of bodily movements (e.g. walking). Where such adaptation is provided, the absorbent product is more easily able to prevent leakage of bodily fluids.
It is therefore another object of the invention to provide an absorbent product which can adapt its width automatically to the width dimensions of-the wearer.
A further problem which presents itself in absorbent products is that the bodily fluid to be absorbed by the product is absorbed at only the upper absorbent surface of the product. Thus, where the flow volume is large and quick, such as with flash incontinence, the absorption characteristics of the absorbent material at the bodyside surface of the product may be such that the absorbent material cannot absorb the fluid fast enough. If such is the case, the fluid can overflow laterally over the edges of the absorbent core. This increases the danger of leakage if the overflow fluid cannot be contained within the side regions of the product to allow sufficient time for absorption. Although the core can be made wider to help alleviate this problem, a wider core implies extra material costs and weight.
It is therefore another object of the invention to provide an absorbent product which has improved absorption characteristics and, in particular, a better rate of absorption.
An additional problem which presents itself in articles which have a friction-increasing means, such as pressure sensitive adhesives provided on the back sheet, is that these means need to be protected from becoming dirty or from sticking undesirably to other objects or clothing before use. To provide said protection it is known to use so-called xe2x80x9crelease paperxe2x80x9d to cover said adhesive. When it is desired to use the product, the release paper (generally in the form of a strip) is peeled away from the underlying adhesive and discarded, thus leaving the adhesive exposed for frictional engagement with the undergarment. In order to facilitate peeling the release paper away from the adhesive, the paper is often treated with a release agent such as silicon.
Several problems arise with the use of such release paper strips. Firstly, the release paper is an element of the product which has to be discarded, which creates a litter problem. Also, the release paper has no further use in the absorption function of the product and thus the provision of such release paper is clearly wasteful and adds to production costs. Furthermore, in use, it has often been found difficult to grasp a non-attached edge of the release paper in order to peel it away from the rest of the product.
A solution to these problems has also been provided by the aforementioned co-pending Swedish application.
One further object of the present invention is however also to provide a product which obviates the use of release paper whilst still providing an effective barrier against direct external contact with an area of the product on which the friction-increasing means may be placed.
Further problems which can be solved by this invention with respect to known absorbent products will become apparent below.
The present invention provides a solution to the aforementioned objects. A solution to at least some of the objects is provided by an absorbent product having the features defined in claim 1.
Preferred features of the invention are defined in the dependent claims.
It should be understood that the term xe2x80x9cfriction-increasing meansxe2x80x9d as used herein, is intended to imply either a surface texture, or a formation on, or coating of, or treatment of, a sheet or layer which has the effect of increasing the resistance of the sheet (and thus the absorbent product) to movement with respect to a user""s undergarment, or alternatively with respect to a liner chassis, when in contact therewith. A pressure-sensitive adhesive is a suitable example of such a friction-increasing means, although different types of adhesive or other sheet treatments will be apparent to a skilled man.
Where particular dimensions are specified in the following description, it will be clear to the skilled man that the widths and lengths of the various components may also be varied in order to suit the particular circumstances. For example, the width and length of the friction-increasing means may vary widely, although typically the width of bands of adhesive may vary between about 4 mm up to several centimeters.